Metallic compositions



July 1965 M. HUMENIK, JR., ETAL 25,815

METALLIC COMPOS ITIONS 4 Sheets-Sheet 1 Original Filed June 22, 1959 cm02mm 44.52 mmIoz 0m moo woo

SBHONI CINV I HVEIM MICHAEL HUMENIKJR DAVID MOSKOWITZ INVENTOR.

J M flaiu ATTORNEYS July 6, 1965 Original Filed June 22, 1959 CUTTINGTIME- MINUTES M. HUMENIK, JR.. ET AL Re. 25,815

METALLIC COMPOSITIONS 4 Sheets-Sheet 2 SAE I045 BHN I63- I74FEED-0.0lI"/REV. DEPTH 0F CUT- o.|oo spasm-e00 SFPM WEAR LAND -o o|o"COOLANT PERCENT MOLYBDENUM IN BINDER(2O MICHAEL HUMENIK,JR

DAVID MOSKOWITZ ,INVENTOR.

ATTORNEYS FIG. 2

July 6, 1965 M. HUMENIK, JR, ETAL Re. 25,815

METALLIC COMPOS ITIONS 4 Sheets-Sheet 3 Original Filed June 22, 1959 2ON 2 mm 2 0w 2 Q GDDIZ him-m; m mmozi m0 wmfimommm m Ow Om ON VBSSENCIHVH MICHAEL HUMEN|K,JR. DAVID MOSKOWITZ INVENTOR.

ZZMMZ (9 ATTORNEYS July 1965 M. HUMENIK, JR. ETAL Re. 25,815

METALLIC COMPOSITIONS Original Filed June 22, 1959 4 Sheets-Sheet 4 o iv F.

m o E |-|J: LL E I 3 5 8 A 9 52' 5-. N .O Q o QF-I-U-I 2%315258 mm emuK, J N

Al I

2O CUTTING TIME MINUTES SHHONI -GNV I HVHM MICHAEL HUMENIK, JR. DAVIDMOSKOWITZ INVENTOR.

A. 44 iii 3m) ATTORNEYS FIG.4

United States Patent Ofice Re. 25,8l5 Roissued July 6, 1965 25,815METALLIC COMPOSITIONS Michael Humenik, Jr., and David Moskowitz, WayneCounty, Micln, assignors to Ford Motor Company,

Dearhorn, Mich, a corporation of Delaware Original No. 2,967,349, datedJan. 10, 1961, Ser. No.

322,048, June 22, 1959. Application for reissue May 21, 1964, Ser. No.380,727

6 Claims. (Cl. 29-182.?)

Matter enclosed in heavy brackets appears in the original patent butforms no part of this reissue specification; matter printed in italicsindicates the additions made by reissue.

This invention is a continuation-impart of that described in applicationSerial No. 722,040, filed March 1 7, 1958, now abandoned.

This invention relates to hard, metallic compositions which areparticularly suitable for cutting bits for machining metals at highspeeds. These compositions are essentially compacts of titanium carbidetogether with molybdenum and a metal of the iron group, particularlynickel. The molybdenum may be added to the compact either as metallicmolybdenum, or as a carbide of molybdenum, or a mixture of metallicmolybdenum and molybdenum carbide. These compacts have been perfected asa decided improvement upon the cemented tungsten carbide tool bits whichnow enjoy widespread commercial acceptance. This invention is related toa metallic composition which for tool bit purposes is a decidedimprovement on the metallic compositions taught in United States LettersPatent to Goetzel et al., 2,581,252, January 1, 1952; Goetzel et al.,2,694,007, November 9, 1954; Redmond et 211., 2,711,009, June 21, 1955;Goetzel et al., 2,752,666, July 3, 1956; Goetzel et al., 2,753,261, July3, 1956, and the compositions described by Humenik and Parikh, TheJournal of the American Ceramic Society, volume 39, Number 2, February1956, pages 60, 61, 62 and 63.

To aid in an understanding of this invention, four figures of drawingshave been presented in which:

FIGURE 1 is a graph in which the abscissa represents the amount of metalremoved in a cutting operation and the ordinate represents thecorresponding tool wear, and

FIGURE 2 is a graph in which the percentage of molybdenum in the bindingalloy is laid out on the abscissa and the cutting time to a definitetool wear is laid out on the ordinate, and

FIGURE 3 is a graph in which the weight percentage of binding alloy islaid out upon the abscissa and the Rockwell A hardness on the ordinate,and,

FIGURE 4 is presented to demonstrate the difference in performancebetween cutting tools based upon solid solutions of molybdenum carbidein titanium carbide and cutting tools fabricated from mixtures ofnickel, titanium carbide and molybdenum carbide, or from mixtures ofnickel, titanium carbide and molybdenum.

A titanium carbide composition essentially free of oxides and nitrideshaving the following analysis was chosen as the base material.

Percent Free carbon 1.2 Combined carbon 19.2

Titanium 78.1

Iron 0.06

The size analysis of: this material as determined by Andraeson particlesize analysis was CUMULATIVE PERCENTAGE OVERSIZE Percent 25 microns 0 15microns 0 5 microns 0 2 microns 26.4 1 micron 49.5

The binding alloy was added as approximately five micron nickel andmolybdenum powder. The metal powder was prepared separately by milling aseventy-five percent nickel, twenty-five percent molybdenum powder andfifty percent nickel, fifty percent molybdenum mixture from minus threehundred twenty-five mesh powder. When necessary small additions of minusthree hundred twenty-five mesh metal powder were used to give a chargeof the desired final composition. The compositions recited in theappended claims refer to the composition of the compact prior to anyreactions which may occur during sintering.

The grinding operations were conducted in a stainless steel millcontaining Hastelloy B balls, benzene being added to inhibit oxidationof the charge during the twenty-four hour milling period. After millingthe henzone was evaporated and four percent wax binder dissolved inbenzene was added. Upon drying the powder was pressed in a steel die ata pressure of about ten tons per square inch.

The cold pressed compacts were presintered in a hydrogen furnace at1200" Fahrenheit for one hour to dewax the specimens. Final sinteringwas performed on an inert stool and in an inert ambient at 2500Fahrenheit for one hour in an induction furnace. An absolute pressure ofabout 0.1 to 0.3 micron was maintained in the furnace although anysuitable inert ambient will be satisfactory. Suitable inert ambieuts aredry hydrogen, argon or helium. The sintering temperature is, of course,a function of sintering time, the time being shortened as thetemperature is raised. In any event the sintering temperature should notexceed 2700 Fahrenheit to avoid substantial grain growth. The time andtemperature of sintering must be adjusted so that the grain size of thetitanium carbide in the finished article is not substantially largerthan that of the starting powder.

it is essential that the binding alloy contain at least ten percent ofmolybdenum to take advantage of the ability of this metal to causealloys containing it to Wet the surface of the hard titanium carbideparticles. Bearing in mind this limitation, it is possible to substituteeither tungsten or chromium or alloys or mixtures of tungsten andchromium for a portion of the molybdenum.

FIGURE 1 clearly shows the superior performance of the cuttingcompositions taught by this invention as compared to commerciallyavailable cemented tungsten carbide compositions. The data presented inFIGURE 1 was obtained by cutting a log of SAE 1045 steel at a Brinellhardness of 163 to 174 with a feed of 0.011 inch per revolution and adepth of cut of 0.100 inch at a surface speed of 350 feet per minute.The two upper curves represent typical cemented tungsten carbideperformance. The three lower curves were obtained using as a cutting bita composition of 65 percent titanium carbide and percent binding alloy,this binding alloy being 70 percent nickel and 30 percent molybdenum.The powders were milled in a steel mill with steel balls for twenty-fourhours under benzene. A wax lubricant was added and the powder waspressed in a steel die at ten tons per square inch. Dewaxing was carriedout at 1290 Fahrenheit for one hour in hydrogen and final sintering wasperformed in vacuo (about 0.1 to 0.3 micron) at temperatures of 2450,2500 and 2550 Fahrenheit for two hours. The hardness of the sintcredspecimens ranged from R 90.0 to 91.0.

FIGURE 2 is presented to show dramatically the ettect of varying theamount of molybdenum in the binding alloy on the durability of thefinished tool in machining tests. The data presented in FIGURE 2 wasobtained in exactly the same manner and under the same circurnstances asthose outlined above in connection with FIG- URE 1 except that thecutting speed was increased to 600 feet per minute. In each case thetool was operated until a land wear of 8.610 inch was observed. Thebinding alloys in these tools were fabricated from molybdenum andnickel. The binding alloy in each case compriscd 20 percent of the massof the tool.

FIGURE 3 shows the hardness of the tool compositions as a function ofthe percentage of binding alloy in the tool composition at fourdifferent levels of molybdenum in the binding alloy. In addition,individual points indicate values at 45, 6t), and percent molybdenum inthe binder.

The graph comprising FIGURE 4 clearly illustrates the contrast inproperties between the cutting tools prepared from titanium carbidewhich is effectively free of dissolved molybdcnum carbide and similartools prepared from titanium carbide containing substantial amounts ofdissolved molybdenum carbide. Since the sintcring temperatures employedin the preparation of the compacts are high enough to permit theconstituents of the compacts to come to equilibrium between thetitanium, molybdenum and carbon, it would appear at first blush to beimmaterial whether the mol elemental molybdenum, as int :1 solidsolution of inolylnlcium c bide.

. can that t addition of niolyh. 1.. in ti tanium carbide trot dec whilethe addition of molybdenum as mum num carbide in cat the curve titaniuror as mo carbide produces URE 4 of the din compact prepared front andnickel. Curve 2 depicts the performance of a compact prepared fromtitanium carbide. hide and nicxcl while cum 3 is con t a bide compactproduced from a solid. clulion of nio denum carbide in titanium carbide.

The composition. preparation and testing detail; of the tools depictedin FIGURE 4 follow:

(I) TiC+ltlhio t iONi l O,v

(2) sllTif l ltloltlosC-t-lllbli (3) il'fiCfldfiMo f) solidsolution+lONi cntbicle.

free carbon The solid solution carbide was prcnared by mi parts TiC andlike parts li'lo C, compacting the n. and sintcring for one hour atlllliltl C. in a J it crucible un-lcr vacuum. X-rv 3 analysis of thesintered slug showed only one phase to be present, i.e., the TiC/Mo Csolid solution. The sintered slug was crushed and milled under benzenein a stainless mill to a fine particle size (less than five microns).The milled solid solution powder was then leached repeatedly in a dilutesulphuric acid solution until substantially all milling impurities wereremoved.

The preparation of the tool composition was similar in powders for 48hours i r. lla'liciloy cc waxing ering in Ii balls, add. the triples inh,

for one h The :eintcr 'l s F. were ground the form of tools. :t'td sndard in.

lcplh of cut 01" cutting :rpccd The tits as shown in Fi l]- that similarcutti.

tamed whe lybdcnnm is add as the metal r carbide, although the additionof molyb illllil ber oi the biarnng alloy is nickel. However, non groupme cite, or their alloys, may be em out departing", from the snirit ofthe invention.

' ty of the d witht t free of detrimental quot an, ar cc: ntrally of ti1am ear hie and a mol bdc .ll con aining i binding alloy, said hi: lingalloy con s gntially of twenty-five percent to seventy perc ol :1...atcrial ccted from the class consisting of molybdenum, molybdenumcarbide and mi tilt of molybdenum and in denurn carbide and an alloyingmetal selected from the group consisting of iron, cobalt, nickel andalloys thcreofi said titanium carbide being essclrtfm'ly free ofdissolved molybdenum and molybdenr'm carbide and said bll in alloy inturn comprising ten to fifty percent of the ma; of the compact, thefor!!! ram'y (fem-m manner of H 5 compact not are edan 13% of the massof the compact.

2. A hard sintc d compact particularl t suitable for cutting tools andcxlnbitnc a ha. vncss of at least on the Rockwell A sca e, Ll con ingfree of detrimental quantities of nit ides and and consisting vlcnnmcon- "iining binding a loy. said binding: al oy consi .inc csscn tiallyof twenty-five percent to seventy percent it material selected from theclass consisting of molybdenum. molybdenum carbide and mix'tures ol ntci tienurn and molybdenum carbide and an alloying metal lected from thegroup consisting of iron, cobalt, nickel and alloys thereof, t 1titanium carbide hcr'fri; essentially free drsrolrcd nmlv/nlcmmz (Jrm'i.' l) \l (l'[ilFJF)I cart-bide and said binding al oy in turn coniprrten to filtv percent of the mass of the com ct, the mm! mm; n content ofthe compact not arc-ceding 13% of the compact.

3. A hard sintcred compact particularh suitable for cutting tools, saidcompact being free of de .ntcl quan titles of nitrides and :rides andconsisting e sentially of titanium carbide and a molybdenum containingbindinw. alloy, said binding alloy consisting essentially of twent fivepercent to seventy percent of a matcri: lccted froin the classconsisting of molybdenum, molybr um carbide and mixtures of molybdenumand mat; and an alloying metal selected from the gr of iron, cobalt,nickel and alloys thereof, said titanium curr'rr'de being essentiallyfree of (limo/awn molybdenum and molybdenum carbide and said bindingalloy in turn comprising ten to fifty percent of the mass of thecompact, said sintering being carried out in an inert ambient at atemperature not substantially above about twentysevcn hundred degreesFahrenheit, the total molybdenum content of the compact not exceeding13% of the mass of the compact.

4. A hard, sintcrcd metallic compac particularly suitable for cuttingtools, said compact lasing free of detriientul quantities of nitridesand oxides and consisting esscntinlly of titanium cur nun: containing.witlc and n molyl binding alloy. said binning alloy consistingessentially of significantly in excess of twcntylive percent to seventypercent of a material selected from the class consisting of molybdenum,molybdenum carbide and mixtures of molybdenum and molybdenum carbide andan alloying mctnl selected from the group consisting of iron, cobalt,nickel and alloys thereof, said titanium carbide being cs- SBI'lllGll)free of dissolved molybtlelzrmz and molybdenum carbide and said bindingalloy in turn comprising ten to fifty percent of the mass of thecompact, the total molybdenum content of the coiizpact not exceeding 13%0 the mass of the compact.

5. A hard sintered compact particularly suitable for cutting tools andexhibiting a hardness of at least 90 on the Rockwell A scale, saidcompact being free of detrimental quantities of nitrides and oxides andconsisting essentially of titanium carbide and a molybdenum contniningbinding alloy, said binding alloy consisting essentially or"significantly in excess of ttventydive percent to .eventy percent of amaterial selected from the class consisting of molybdenum, molybdenumcarbide and mixtures of molybdenum and molybdenum carbide and analloying metal selected from the group consisting of iron, cobalt,nickel and alloys thereof, said titanium carbide being essentially freeof dissolved molybdenum and molybdenum carbide and said binding alloy inturn comprising ten to fifty percent of the mass of the compact, thetotal molybdenum content of the compact not exceeding 13% of the mass ofthe compact.

A hard sintcred compact particularly suitable for cutting tool. aidClill.ttClI being free of detriment-til quan- .md oxides and consistingcssentislly of rnitnn Ci'lil l and n molybdenum containing binding I.said binding alloy consisting essentially of significantly in excess oftwenty-five percent to seventy percent of a material selected from theclass consisting of molybdenum, iOl}l.lLlCill.ill1 carbide and mixturesof molybdenum and molybdenum carbide and an alloying metal selected fromthe n'oup consisting of iron, cobalt, nickel and alloys lhcrcof. milltiimzimn carbide being essentially free of dissolved molybdenum andmt'Jlybdent m carbide and said binding nlloy in turn comprising ten tofifty percent of the mass of the compact, said sintering being carriedout in an inert ambient at a temperature not subs itinlly above abouttwenty-seven hundred degrees Fahrenheit, the total molylm'ennm contentof the compact not exceeding 13% of the mass of the compact.

OTHER REFERENCES Powder Metallurgy Bulletin, Volume 4, No. l, Yonkers,NY. January 1949. Page 13. TN695 P56.

CARL D. QUARFORTH, Primary Examiner.

BENJAMEN R. PADGETT, Examiner.

1. A HARD SINTERED METALLIC COMPACT PARTICULARLY SUITABLE FOR CUTTINGTOOLS, SAID COMPACT BEING FREE OF DETRIMENTAL QUANTITIES OF NITRIDES ANDOXIDES CONSISTING ESSENTIALLY OF TITANIUM CARBIDE AND A MOLYBDENUMCONTAINING BINDING ALLOY, SAID BINDING ALLOY CONSISTING ESSENTIALLY OFTWENTY-FIVE PERCENT TO SEVENTY PERCENT OF A MATERIAL SELECTED FROM THECLASS CONSISTING OF MOLYBDENUM, MOLYBDENUM CARBIDE AND MIXTURES OFMOLYBDENUM AND MOLYBDENUM CARBIDE AND AN ALLOYING METAL SELECTED FROMTHE GROUP CONSISTING OF IRON, COBALT, NICKEL AND ALLOYS THEREOF, SAIDTITANIUM CARBIDE BEING ESSENTIALLY FREE OF DISSOLVED MOLYBDENUM ANDMOLYBDENUM CARBIDE AND SAID BINDING ALLOY IN TURN COMPRISING TEN TOFIFTY PERCENT OF THE MASS OF THE COMPACT, THE TOTAL MOLYBDENUM CONTENTOF THE COMPACT NOT EXCEEDING 13% OF THE MASS OF THE COMPACT.